Electrical connector



Jan. 25, 1966 R. J. KILBURG 3,231,850

ELECTRICAL CONNECTOR Filed Oct. '7, 1965 2 Sheets-Sheet 1 Jan. 25, 1966 R. J. KILBURG 3,231,850

ELECTRICAL CONNECTOR Filed 001;. '7, 1963 2 Sheets-Sheet 2 INVENTOR. 5% @04/410 J Mia/m irrrom/n' United States Patent Ofiice 3,231,850 Patented Jan. 25, 1966 3,231,850 ELECTRICAL CONNECTOR Ronald, J. Kilburg, Belmont, Calif, assignor to Insnl-8 Corp., San Carlos, Calif., a corporation of California Filed Oct. 7, 1963, Ser No. 314,291 2 Claims. (Cl. 339-213) This invention relates generally to connectors and more particularly to connectors for electrically joining multistrand wire cables of dilterent sizes.

In systems in which electrification systems are used to transfer current mobile power and control circuits, it is necessary to provide some means for connecting such external circuits to the collector head of the system. Previously, this hook-up has been accomplished by the user wiring his own multi-strand power cable into a terminal block forming an integral part of the current collector means or by connecting it directly to the head and taping it to parts of the collector means.

One of the disadvantages of allowing a customer or user of an electrification system to connect hisown power cable directly to the contact shoe ofthe current collector is that he will often fail to take intoaccount the extreme conditions under which such electrification systemsusually operate. The contact shoe which runs along the fixed conductor bar of the system must have freedom to move in all directions; therefore, any cable connected from the shoe to a power control circuit must withstand large bending and vibrational stresses.

In order to compensate for these extreme but normal operating conditions, mobile systems should be provided with extra-flex, multi-strand cables which are designed to absorb the generated energy properly. In too many cases, however, relatively inflexible cable is connected to the shoe. Not only do suchcablestendto fatigue and break after a short period of time but inflexible cables will cause the operationof the electrification systems to be degraded.

Then, too, because such systems more often than not use a plurality of collector head assemblies associated with a series of conductor bars which are mounted in close proximity. to one another,v the. cables connecting the power and control circuits to the. respective collector heads should be dressed and maintained in fixed planes to avoid lateral interference. Failure to do this results in the degeneration of the operation of the entire electrification system.

To cope with. these problems, a simple connector has been devised to accept one end of an extra-flex cable which is connected at its other end to the collector head and selected to insure proper operation. of the overall mobile system. Moreover, the. connector destructably clamps the extra-flex cable to discourage users from connecting relatively inflexible cables. to the collector head.

The principal objects of the present invention, therefore, are to provide an insulated electrical connector that is easy to fabricate, economical to manufacture, simple in operation, and which will. accept, within limits, diiferent Size cables.

A more specific object of the invention is to provide an electrical connector for use with electrification systems of the type described which is destructibly connected to the electrification system pigtail cable at one end and impermanently connected tothe cableof a remote power and control circuit at its other end-eall to the end that the electrification system will operate satisfactorily.

In a preferred embodiment .of the present invention, an extra-flexure cable is connected between the collector shoe of the electrification system and the destructible end of the connector forming the subject matter of the instant invention. The means by which the connector secures the pigtail cable and the power and control circuit cable form a material part of the instant invention.

The exemplary embodiment of the electrical'connector has three principal features. First, at one end means are provided for properly positioning the stripped end of the pigtail cable interior one end of the connectorirnmediately adjacent a pair of flanges formed by an interior section of the body of the connector. These flanges are destructibly moved inwardly in the normally tubular body to clamp the pigtail wire against an inside wall of the tube. Second, in the other end of the connector there is provided a pad with externally controllable means for adjusting its movement transverse to the longitudinal axis of the connector body so that it will act to grip the ends of a stripped cable from a power and control circuit between the pad and an inner surface of the body. And third, an insulating cover is provided for threadedly or otherwise over-riding the connector body to insulate it from external effects or contact by personnel using the system or power and control circuits associated with it.

Broadly, the present invention is. an insulated connector for electrically joining cables which combines crimp.- ing means to lock one cable interior of the connector and means to impermanently secure another cable interior thereof.

These and other objects, advantages and features of the present invention may be more fully understood when the following detailed description is read with reference to the drawings in which:

FIG. 1 illustrates the component parts of an exemplary electrification system including the electrical connector forming the subject matter of the present invention;

FIG. 2 is a partial cross-sectional view of the electrical connector;

FIG. 3 is a plan view of the connector of FIG. 2;

FIG. 4 is a section view taken along line 4-4 of FIG. 2 showing the end of the connector in which the pigtail assembly of the electrification system is destructibly and permanently connected; and,

FIG. 5 is a section taken along line 55 of FIG. 3 illustrating the construction of the movable pad and adjusting means therefor.

Looking generally to FIG. 1, a typical electrification system can be seen to include one or more conductor bars 1 1 of generally figure 8 cross-section and one or more current collector means or assemblies 17 supported to slidably contact the conductor bars. The conductor bar 11 is mounted on an I-beam track by hanger clamps 12 and the current collector 17 is mounted on a carriage 14 which is moveable along the track. All but one longitudinal surface of the bar 11 is normally covered with an insulating sheath 13.

The current collector means 17 includes a contact shoe 19 supported by a collector head 18 which is connected to one end of an arm 22. The arm 22 in turn is pivotally connected at its other end to a collector base 23., A collector spring 24 urges contactshoe 19 against the exposed, surface of the collector bar 11.

The pigtail assembly of the collector means includes the extra-flex pigtail cable 26, the anchor or loop clamp.

27 attaching it to the collector base and connector 30.

An example of an extra-flex cable satisfactory for use with an electrification system capable of handling a ampere load is the No. 4 cable manufactured by the Simplex Wire and Cable Company of Cambridge, Massaehusetts. This cable has 1078 strands of No. 34 wire and insulating cover rated at 600 v.

The operation of this electrification system can be described briefly. Assembly 17 is restricted to move along the path of the collector or current bar 11 but with suflicient freedom to allow side-to side and up-and-down movement. Because of this multidegree of freedom movement of the collector head and shoe member, the cable 26 is subjected to a substantial amount of flexing.

Bending stresses build up at the point of attachment to the contact shoe 19, at the anchor or loop clamp 27, and adjacent the connector 30.

In many cases the customer or user of such electrification systems will connect his own cable 31 to the collector head 18. If it is not the proper type of cable, fatigue will shortly cause the cable insulation and/or wire to break. This will require the service to be interrupted while the entire carriage assembly is removed from the track so that the cable connected to the lower part of collector head 18 can be replaced.

The present invention provides a ready means for connecting the power and control circuit cable 31 to the system without endangering its proper operation. Looking more particularly to FIGS. 2 through 5, connector 30 is shown to include a generally tubular body member 29 and an insulating cover 32 captured on the flexible cable 26.

Tubular body member 29 includes a reduced section 33 at one end and an enlarged section 34 at its other end. Intermediate or towards the inner side of the enlarged portion 34 is a threaded portion 35 adapted to receive threads 36 formed inside of the insulating cover 32. With threaded sections 35 and 36 in mating relation, the insulating cover 32 completely encompasses the connector body 29 thereby preventing contact with the connector body itself.

It will also be noted that the insulating cover or sleeve 32 has a shoulder 38 at the left edge (with respect to the left side of the FIG.2 drawing) of threads 36 which will abut a shoulder 39 on the connector body 29 to prevent further movement of the insulating cover to the left. The cover 32 is adapted to move from left to right to expose the connector body 29 but it cannot be moved beyond the connector body in the direction of the customers cable 31. The insulating cover 32 is movable along the pigtail cable 26 so that the connector can be connected to customers cable and so that it cannot be lost.

The connector body 29 is hollow in the exemplary embodiment, but it is only necessary that it be partially apertured to encompass the sheath of the pigtail cable 26. When the end 46 of the sheath on the cable 26 abuts shoulder 47, formed interior of the connector body 29, it positions the stripped portion 49 of the pigtail cable 26 immediately under the section of the connector generally designated as 51.

The crimping section or means 51 for the pigtail cable 26 is formed by cutting a pair of more or less rectangular flanges 53 in one section of the connector body 29, as particularly illustrated in FIG. 3. With the stripped end 49 of the cable 26 positioned directly under the flanges 53, they are displaced interior of the connector body 29 to force the stripped end of the cable 26 against an inner wall of the body 29. By driving the flanges 53 inwardly, it is difiicult if not impossible to substitute cables.

At the other end of connector body 29 there is provided a pressure pad 61 disposed generally along the longitudinal axis of the connector body 29. It generally has an arcuate shape, as particularly illustrated in FIG. 5. The pad 61 is apertured on its concave side to receive a flanged end 62 of an Allen set screw 63 or the like, which acts as a universal or ball joint. Set screw 63 is threaded through the side of connector body 29 so that pad 61 may be externally moved against an inside surface of the connector body 29 to grasp a wire therebetween.

It will be noted that the arcuate configuration of the pressure pad (see FIG. is such that the distance marked a between the edge of the pressure pad and the interior surface of the connector body 29 is too small for the end 71 to normally move therebetween. Hence, it cannot become lodged between the threads of the set screw and an interior wall of the connector body 29. This assures that the pressure pad 61 always acts positively against the stripped end 71 to force it against an inside surface of body connector 29.

Normally, electrification systems such as those described briefly above have current collectors for different service loads. This being the case, the size of the opening in the end of the connector that receives the cable from a remote power consuming device can be proportioned to accept cables up to the rated capacity of the collector means but not beyond. By this means, it is possible to substantially prevent users from overloading the collector means of the system.

While the present invention has been described with reference to an exemplary embodiment, it should be understood that various other configurations and modifications can be envisioned by those skilled in the art without departing from the spirit and scope of the present invention.

What is claimed is:

1. A connector for joining electrical cables comprising, in combination,

a body member having two ends,

first and second insulated cables having one set of their ends stripped of their insulating sheaths,

one end of said body member having a first opening formed therein to accept the sheath of said first cable,

a shoulder formed longitudinally interior of said first opening to stop the interior movement of the insulating sheath of said first cable,

said one end also having at least one flange formed of a section of said body member intermediate said ends,

said flange movable interior of said body member to irreversibly and securely hold the stripped end of said first cable,

the other end of said body member having a greater external cross-section than said one end and having an opening therein adapted to accept the sheath of said second insulated cable,

a movable pressure pad interior of said other end,

means cooperating with said body member externally operable to move said pad into abutting relation with an inner wall of said body member, and a hollow elongate insulating cover captured on said cable by said body member and adapted to slide over said body member to fully enclose said body and prevent external contact therewith.

2. A connector for joining electrical cables of different wire sizes comprising, in combination,

a hollow metal connector body having a longitudinal axis therethrough and two end portions, one end portion of reduced external cross-section;

first and second insulated cables having one set of their ends stripped of their insulating sheaths;

said second cable having a preselected diameter not necessarily the same as that of said first cable;

the one end portion of said body adapted to accept the sheath of said first cable;

a shoulder longitudinally disposed interior of the first end portion to stop the interior longitudinal movement of the insulating sheath of said first cable;

said first end also having transversely oriented flanges formed intermediate said two end portions and movable interior of said body to irreversibly and securely hold the stripped end of said first cable against a wall of said connector body;

the other end portion of said connector body having a greater external cross-section than said one end and having an opening therein adapted to accept the sheath of said second insulated cable even when it is of a different diameter than said first cable;

a movable pressure pad having a pre-selected width disposed along said longitudinal axis interior of said other end;

locking means externally operable to move said pad transversely into abutting relation to an inner wall of said connector body;

the Width of said pad pre-selected to prevent the wire of said second cable that is to be secured between the pad and an interior wall of said body from lodging between the pad and said locking means;

a series of threads formed on the outer surface of the larger cross-section part of said body member intermediate said two ends; and,

a tubular insulating cover longer than the connector body and adapted to fit over it,

said cover having threads formed along an intermediate interior portion thereof to engage the threads on said body member when the cover fully surrounds said connector body and an internal shoulder to abut a part of said other end portion immediately adjacent the external threads on said connector body so that the cover cannot be moved longitudinally over said other end portion.

References Cited by the Examiner UNITED STATES PATENTS 6/1934 Riccardi et al. 339237 10/ 1934 Wiseman 17484 X 3/1936 Douglas. 6/ 1936 Hoover 339272 X 4/1939 Genter 19159.1

11/ 1942 Churchward 3 39213 X 9/ 1944 Williams 339268 X 3/1950 Cafiero 339272 10/1950 Cripe 339272 2/ 1963 Zimmerman 339223 X 1/ 1965 Lynch et al 339223 X FOREIGN PATENTS 4/ 1913 Austria. 10/ 1947 Great Britain.

20 JOSEPH D. SEERS, Primary Examiner.

R. E. MOORE, Assistant Examiner. 

1. A CONNECTOR FOR JOINING ELECTRICAL CABLES COMPRISING, IN COMBINATION, A BODY MEMBER HAVING TWO ENDS, FIRST AND SECOND INSULATED CABLE HAVING ONE SET OF THEIR ENDS STRIPPED OF THEIR INSULATING SHEATHS ONE END OF SAID BODY MEMBER HAVING A FIRST OPENING FORMED THEREIN TO ACCEPT THE SHEATH OF SAID FIRST CABLE, A SHOULDER FORMED LONGITUDINALLY INTERIOR OF SAID FIRST OPENING TO STOP THE INTERIOR MOVEMENT OF THE INSULATING SHEATH OF SAID FIRST CABLE, SAID ONE END ALSO HAVING AT LEAST ONE FLANGE FORMED OF A SECTION OF SAID BODY MEMBER INTERMEDIATE SAID ENDS, SAID FLANGE MOVABLE INTERIOR OF SAID BODY MEMBER TO IRREVERSIBLY AND SECURELY HOLD THE STRIPPED END OF SAID FIRST CABLE, THE OTHER END OF SAID BODY MEMBER HAVING A GREATER EXTERNAL CROSS-SECTION THAN SAID ONE END AND HAVING AN OPENING THEREIN ADAPTED TO ACCEPT THE SHEATH OF SAID SECOND INSULATED CABLE, A MOVABLE PRESSURE PAD INTERIOR OF SAID OTHER END, MEANS COOPERATING WITH SAID BODY MEMBER EXTERNALLY OPERABLE TO MOVE SAID PAD INTO ABUTTING RELATION WITH AN INNER WALL OF SAID BODY MEMBER, AND A HOLLOW ELONGATE INSULATING COVER CAPTURED ON SAID CABLE BY SAID BODY MEMBER AND ADAPTED TO SLIDE OVER SAID BODY MEMBER TO FULLY ENCLOSE SAID BODY AND PREVENT EXTERNAL CONTACT THEREWITH. 